DD is 11. Tonight we were at the park with our dog. There's a slide that's on a hill so it doesn't have steps up to it. She was standing at the top and about to throw DDogs ball when DDog knocked it out of her hands and it rolled down the slide. DDog jumped on the slide without thinking and went sliding down after it, pretty gracefully actually. DD thought it was hilarious but I told her to keep DDog and the ball away from it as DDog had been lucky not to get hurt.
Half hour later I'm across the park pushing DS on the swings and I see DD drop the ball down the slide. DDog goes to run away from the top of the slide and down the hill alongside it but DD blocks DDog so DDog slips down backwards and twists halfway down (it's not a straight slide.) Again, DD is in hysterics.
When I tell her off she says she didn't mean to and that it was an accident. Her sister backs up what I saw - that she dropped it and blocked DDog deliberately. As I was putting the DC to bed I saw that DDog isn't bearing weight on one of her legs and told DD so. She said "fine, I'm sorry" and stroked DDog. AIBU to think that doesn't cut it and to be absolutely livid? She messaged her dad about it who messaged me saying she's done nothing wrong 